82 xjs regular gas?
 

Hey all. I just bought a sales brochure for my 82 and where it described the "new" HE head design, the article states, and I quote. " This enables the engine to run on a leaner mixture and a higher compression using regular unleaded fuel". So, if I understand that properly then I've been wasting money by using premium all these years. Or, am I missing something somewhere in that statement? Does anyone have info on this. I'd love to save some money. Thanks. Bud

Octane ratings have changed since that was written. What was originally considered regular is now premium gas. Also, if I'm not mistaken, Europe has a different method of rating octane levels.